The purpose of this paper is to analyze the colonial internal trade at the beginning of the nineteenth century. The market segment focused in the study is the cattle trade to Rio de Janeiro, based on a tax charged for the animals on the way from São Paulo to Rio de Janeiro. The growth of the city of Rio de Janeiro, mainly after the arrival of the Royal Court from Portugal, required a significant increase in the flow of goods on that route. However, even before the Court's arrival the market was already very expressive. Finally, the study also shows that cattle trading was a business in the hands of a merchant elite.